Commit bf5add39 authored by Swarup Laxman Kotiaklapudi's avatar Swarup Laxman Kotiaklapudi Committed by Andrew Morton
Browse files

proc: test ProtectionKey in proc-empty-vm test 

Check ProtectionKey field in /proc/*/smaps output, if system supports
protection keys feature.

[adobriyan@gmail.com: test support in the beginning of the program, use syscall, not glibc pkey_alloc(3) which may not compile]

Link: https://lkml.kernel.org/r/ac05efa7-d2a0-48ad-b704-ffdd5450582e@p183


Signed-off-by: default avatarSwarup Laxman Kotiaklapudi <swarupkotikalapudi@gmail.com>
Signed-off-by: default avatarAlexey Dobriyan <adobriyan@gmail.com>
Reviewed-by: default avatarSwarup Laxman <Kotikalapudi&lt;swarupkotikalapudi@gmail.com>
Tested-by: default avatarSwarup Laxman <Kotikalapudi&lt;swarupkotikalapudi@gmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 20e34aa7

tools/testing/selftests/proc/proc-empty-vm.c

+61 −18
Original line number Diff line number Diff line
@@ -23,6 +23,9 @@ 
 *	/proc/${pid}/smaps

 *	/proc/${pid}/smaps_rollup

 */

#undef _GNU_SOURCE

#define _GNU_SOURCE



#undef NDEBUG

#include <assert.h>

#include <errno.h>
@@ -34,6 +37,7 @@ 
#include <sys/mman.h>

#include <sys/ptrace.h>

#include <sys/resource.h>

#include <sys/syscall.h>

#include <sys/types.h>

#include <sys/wait.h>

#include <unistd.h>
@@ -42,6 +46,43 @@ 
#define TEST_VSYSCALL

#endif



#if defined __amd64__

	#ifndef SYS_pkey_alloc

		#define SYS_pkey_alloc 330

	#endif

	#ifndef SYS_pkey_free

		#define SYS_pkey_free 331

	#endif

#elif defined __i386__

	#ifndef SYS_pkey_alloc

		#define SYS_pkey_alloc 381

	#endif

	#ifndef SYS_pkey_free

		#define SYS_pkey_free 382

	#endif

#else

	#error "SYS_pkey_alloc"

#endif



static int g_protection_key_support;



static int protection_key_support(void)

{

	long rv = syscall(SYS_pkey_alloc, 0, 0);

	if (rv > 0) {

		syscall(SYS_pkey_free, (int)rv);

		return 1;

	} else if (rv == -1 && errno == ENOSYS) {

		return 0;

	} else if (rv == -1 && errno == EINVAL) {

		// ospke=n

		return 0;

	} else {

		fprintf(stderr, "%s: error: rv %ld, errno %d\n", __func__, rv, errno);

		exit(EXIT_FAILURE);

	}

}



/*

 * 0: vsyscall VMA doesn't exist	vsyscall=none

 * 1: vsyscall VMA is --xp		vsyscall=xonly
@@ -84,10 +125,6 @@ static const char proc_pid_smaps_vsyscall_1[] = 
"SwapPss:               0 kB\n"

"Locked:                0 kB\n"

"THPeligible:           0\n"

/*

 * "ProtectionKey:" field is conditional. It is possible to check it as well,

 * but I don't have such machine.

 */

;



static const char proc_pid_smaps_vsyscall_2[] =
@@ -115,10 +152,6 @@ static const char proc_pid_smaps_vsyscall_2[] = 
"SwapPss:               0 kB\n"

"Locked:                0 kB\n"

"THPeligible:           0\n"

/*

 * "ProtectionKey:" field is conditional. It is possible to check it as well,

 * but I'm too tired.

 */

;



static void sigaction_SIGSEGV(int _, siginfo_t *__, void *___)
@@ -240,19 +273,27 @@ static int test_proc_pid_smaps(pid_t pid) 
		}

		perror("open /proc/${pid}/smaps");

		return EXIT_FAILURE;

	} else {

	}

	ssize_t rv = read(fd, buf, sizeof(buf));

	close(fd);



	assert(0 <= rv);

	assert(rv <= sizeof(buf));



	if (g_vsyscall == 0) {

		assert(rv == 0);

	} else {

		size_t len = strlen(g_proc_pid_smaps_vsyscall);

			/* TODO "ProtectionKey:" */

		assert(rv > len);

		assert(memcmp(buf, g_proc_pid_smaps_vsyscall, len) == 0);



		if (g_protection_key_support) {

#define PROTECTION_KEY "ProtectionKey:         0\n"

			assert(memmem(buf, rv, PROTECTION_KEY, strlen(PROTECTION_KEY)));

		}

		return EXIT_SUCCESS;

	}



	return EXIT_SUCCESS;

}



static const char g_smaps_rollup[] =
@@ -419,6 +460,8 @@ int main(void) 
		abort();

	}



	g_protection_key_support = protection_key_support();



	pid_t pid = fork();

	if (pid == -1) {

		perror("fork");